Hi:
I am more I incline to go with the camera with an integrated gps
watching the back deck idea. Excellent deterrent!!
You get photo, time, and Lat-Long. If bandwidth is a problem make sure
the camera has a hard disk for storage. Do not use live feed. Down load
it when the boat returns to port. If the camera unit is "lost at
sea" seize the boat and disappear the skipper's first born.

But how do you estimate catch size? When I worked F/T I painted marks
on poles (maybe sorting boards on your boats) and the trawl deck at
every so many parts of a meter at various spots. Sort of reminded me of
how a football field is marked. That way I could get a very rough
estimate of the size of the codend/bag. It aint real accurate, but at
least ya got a reference. Then you can use some sort of a
volume/density calculation (volume of a cylinder) to approximate the
weight. Like I said before if it floats the density is 1.0 in your
volume/density calculation. If you get real fancy instead of a cylinder
you could use the volume of a "semi ellipsoidal solid" if that was
more the shape of your codend. Damn, starting to sound a bit nurdy.

May sound like BS but it is a method approved by NMFS and in
conjunction using other methods would work for your needs. Ya know,
comparing photo estimate to the actual weight of catch delivered. I was
usually about 10 MT off on a 80-100 MT bag. So were talking about
80%-90% accuracy.

Another way is if your fishers are using reasonably "modern" nets
the codend should have a series of parallel "bands" that act much
like ribs on a wood boat to help maintain the shape of the codend. The
area between each band will have a volume when full. The midwater
Pollock guys in the Bering could usually call their tonnage about as
close as I could simply by counting the full bands in their bags. In
your case maybe three bands = 6 MT? Just guessing. I am assuming that
your 12 M boats are landing not much more that 2-10 MT per tow???

How to keep the fishers from selling fuel? Put a government seal on
their gas cap. The trucking industry uses seals on the door of the
trailer. Or a simple lock. If your boats return lockless tell them to
shove off and buy subsidized fuel someplace else. Hey........ you could
put one of those tags on the lock like a mattress has, ya know "under
the penalty of law...."

I got a bad feeling about the tow rope tension/drag sensor idea. Too
many variables and no visual evidence that a camera produces. There are
tricks a skipper can do to fool a drag sensor. Same for the RPM/torque
idea. Although most the old salts dragging on the west coast would use
a drop in rpm to indicate a full codend. But back then though, a
typical dragger was wood, 31 GRT, measured 48x13.5x7, and was powered
by a 6-71. Big difference compared to a 180' ex OSV packing twin EMDs
and towing a net with its doors spread a ¼ mile apart. And people
wonder why there are no cod left?

There you go. Problem solved.

Last though, since the host nation's RFP wants you to show yours first
try this. Give them three different bids:
1) Big $$ space age satellite tracking stuff.
2) Middle $$ Camera with gps and mass storage device that lasts for
duration of trip.
3) Little $$ On board observers funded by landing tax.

Good luck.
Bob